This invention relates to a branch fitting for a pipe and, more particularly, to a branch fitting having positive alignment means for self-alignment and self-jigging of the fitting relative to an opening in the pipe.
Branch fittings of the type contemplated by the invention are used in a wide variety of fluid conducting installations and provide an extremely advantageous return bend connection for equipment using coils (either for heating or cooling).
Inasmuch as the fittings (as well as the types of tubing to which they are attached) are of relatively small size, it is important that the interior walls of the fittings as well as the tubing be relatively smooth having a fairly uniform inside diameter so as not to restrict fluid flow. Additionally, because these fittings are often integrated into coil equipment and the like, as by brazing or other heat employing uniting operations, it is important that the fitting be permanently attached to the tubing so as to prevent internal flow restrictions even in size-for-size joints thereby providing full flow characteristics.
The invention herein is specifically directed to a branch fitting for permanent attachment to the periphery of a pipe having a tubular portion with an inner diameter less than or the same as the inner diameter of the pipe, a saddle portion surrounding and extending outwardly and downwardly from the base of the tubular portion and having its under surface generally conforming to the outer surface of the pipe, and positive alignment means integral with the fitting at the junction of the saddle portion and the tubular portion for self-alignment and self-jigging of the fitting relative to an opening in the pipe. It is notable that the provision of such a fitting prevents the formation of internal flow restrictions in the pipe or the fitting as the fitting is permanently attached to the pipe such as by brazing. The positive alignment means advantageously renders the fitting self-aligning and self-jigging in all planes in a manner which prevents any relative lateral, longitudinal, and rotational movement between the fitting and the pipe as the fitting is permanently attached to the pipe. It will also be seen that the positive alignment means is preferably in the form of an extended pilot projecting downwardly from the junction of the saddle portion and the tubular portion a maximum distance the same as or greater than the thickness of the pipe. The pilot is advantageously circumferentially interrupted at two diametrically opposed positions forming a coaxial extension of the tubular portion and having a diameter equal to the diameter of the tubular portion wherein the tubular portion adjacent the saddle portion can be coaxial with the opening in the pipe as the fitting is permanently attached to the pipe. It is further notable that the provision of such a fitting preferably includes the saddle portion extending downwardly below the center line of the pipe and including opposing ends that extend outwardly and opposing sides that extend outwardly and downwardly from the base of the tubular portion. With these and still additional features described in detail hereinafter, a branch fitting is provided having significant advantages over prior art fittings.
The problems associated with prior art fittings such as those illustrated in U.S. Pat. Nos. 1,908,821, 1,977,112 and 3,649,055 have been solved through the employment of positive alignment means integral with the fitting at the junction of the saddle portion and the tubular portion. I have found that by forming a downwardly projecting extended pilot it is possible to provide a fitting that is self-aligning and self-jigging relative to an opening in the pipe in a manner preventing the formation of internal flow restrictions in the pipe or the fitting as the fitting is permanently attached to the pipe. The prior art previously required the fitting to have an inner diameter smaller than the inner diameter of the pipe and even then encountering difficulties in permanent attachment since such fittings were neither self-aligning nor self-jigging requiring the relatively time consuming use of special jigs that are expensive to use and less than fully effective during brazing or other attachment procedures. I have further found that fittings heretofore used would oftentimes shift slightly as they were being permanently attached to a pipe resulting in an even greater restriction to flow through the smaller inner diameter fittings as well as a weaker joint caused by the fact that there would be brazing only at the ends. With the features of my invention, I provide a branch fitting for permanent attachment to the periphery of a pipe with fully unimpaired flow, self-alignment and self-jigging in a size-for-size joint that is at least as strong as the strength of the pipe and fitting components.
Other objects and advantages of the invention may be seen in details of the ensuing specification.